Autolube Pump; Crankshaft; Primary Sheave - Yamaha YQ50 Service Manual

INSPECTION AND REPAIR

AUTOLUBE PUMP

Wear or an internal malfunction may cause the
pump output to vary from the factory setting.
This situation is, however, extremely rare. If
improper output is suspected, inspect the
following:
1. Inspect :
• Delivery line
Obstructions © Blow out.
• O-ring
Wear/Damage © Replace.
2. Inspect :
• Autolube pump drive gear teeth Q
• Autolube pump driven gear teeth W
Pitting/Wear/Damage © Replace.
314003

CRANKSHAFT

1. Measure :
• Crankshaft width "A"
• Runout limit "C"
• Connecting rod big end side clearance "D"
Use V-blocks, dial gauge and thickness gauge.
308001

PRIMARY SHEAVE

1. Inspect :
• Primary sliding sheave Q
• Primary fixed sheave W
Wear/Cracks/Scratch/Damage © Replace.
319006
4-16
ENG
Crankshaft width "A" :
37.90 ~ 37.95 mm
(1.492 ~ 1.494 in)
Runout limit "C" :
0.03 mm (0.0012 in)
Connecting rod big end side
clearance "D" :
0.2 ~ 0.5 mm (0.008 ~ 0.02 in)